Idea thermal management materials required the combination of extraordinary high TC, excellent electrical insulation, excellent flexibility and easy processability. Carbon-based fillers such as graphene, owing to their extraordinary high intrinsic TC, have recently attracted attention as fillers to improve the TC of polymer-based thermal management materials. However, the addition of a few carbon filler will unavoidably cause the great deterioration of electrical insulation performance, which hinders the wide use of these thermal management materials in electric or electronic devices field. In order to provide thermal conducting but electrically insulating polymer-based thermal management materials, ceramic-based fillers such as BN, were used. But the intrinsic TC of ceramic-based fillers is much lower than carbon-based fillers. Thus, the TC of ceramic-based thermal management materials always cannot reach expected TC improvement compared to carbon-based thermal management materials. In this work, a high-performance thermal management materials based on integrating the advantages of BN(electrical insulation) and graphene nanoplateles (GNPs, high thermal conductivity) as fillers was realized by a facile scalable strategy. Outstanding thermal conductivity (TC) of 8.45 W m-1 K-1, the highest value among electrical insulating polymer-based materials, excellent electrical insulation of 〖"10" 〗^"12" " Ω cm" and superior EMI shielding performance was achieved with fillers loading of 17.88 vol%. Moreover, the mechanical property and hardness also have been kept in quite good range. These results suggest a promising method in industry production of superior thermal management materials.